class Solution1 {
    public int findPeakElement(int[] arr) {
        int left=0,right=arr.length-1;
        while(left<right) {
            int mid = left+(right-left+1)/2;
            if(arr[mid]>arr[mid-1]) left=mid;
            else right=mid-1;
        }
        return left;
    }
}